350 magnum efi 95

[warrenfine]

Re: 350 magnum efi 95

moriverrat

i have just checked out the info on "efi vapor lock"

the symptoms that i have read about are exactly what i am experiencing.
i changed the thermostat a while back and i think the problem started at about then and according to the merc service bulletin on this topic - this might have started the problem. (the old one was rusted through)


thanks

warren

 

[imported_MORIVERRAT]

Re: 350 magnum efi 95

OK, so lets see if I can follow this - your old thermostat wasn't letting the engine come up to temperature, because it was rusted through, and wouldn't regulate the water temperature in the engine. If the engine dosn't get up to proper temperature, the ECU thinks the engine has just started and runs a rich mixture. that might explain the fouling of the plugs. If you want to troubleshoot the vapor lock, you can "T" in your fuel pressure gage to the line running to the TBI. THe pressure should be around 30 psi. (confirm that in your manual) If it is vapor lock, you will see the pressure slowly drop as you try to start the engine, and eventually fall off to zero. (all this time, you can hear the pump running). If the pump's running, and you got no pressure, you probably got vapor lock.

 

[warrenfine]

Re: 350 magnum efi 95

i just had a look at the engine the fuel pump sits on top of the intake manifold - there is no fuel box - the pipes on the thermo housing go to exhaust manifolds - nothing to "fuel box"

is the vapor lock caused by the heat perculating into the pump then...........

have i missed somthing ?
there is an auxilary cam driven fuel pump which goes through a fuel filter then into a high preasure fuel inj pump.

where will the vapor lock occur in the high preasure pump how can i avoid this .......... i tried the blower and opening the cover a bit and idling the boat for ten mins.
probelm still seems to occur 30min to 3 hrs after use.

the symptoms say vapor lock........................

warren